A fuel pump is used to move an amount of fuel from a fuel source to a fuel delivery system of an internal combustion engine. Depending on the type of fuel delivery system, such as a carburetor, throttle body injection system, port injection system, or direct fuel injection system, the fuel may be delivered at a relatively low- or high-pressure level. For example, a fuel injection system typically requires the fuel to be delivered at a higher pressure than does a carburetor.
Spark Ignition Direct Injection (SIDI) engines typically employ a high-pressure fuel pump that is driven by a camshaft used for valve train actuation of the internal combustion engine. It is beneficial to drive the fuel pump with the camshaft or a camshaft drive mechanism since certain aspects of pump operation may need to be synchronized with the engine.
Potential benefits of SIDI include a substantial increase in engine power, improved fuel economy, smoother starting, and reduced tailpipe emissions. However, as the higher pressure fuel injection pump systems used with SIDI engines typically employ rail pressures of approximately 150 to 200 bar, the performance of such assemblies may be less than optimal under certain conditions, particularly during periods when the engine is running at a relatively low speed.